1. Field of the Invention
This invention relates to electrical switching devices and, more particularly to interlock means for preventing separation of stacked switch blocks.
2. Description of the Prior Art
Electric switches are frequently provided with separable contact blocks and switch operator. The contact blocks are mounted within an enclosure and a switch operator is mounted for manual access on the enclosure cover and cooperates with the contact blocks when the blocks are in the closed position. One type of switch operator is the push-button type which actuates a series of stacked contact blocks which are secured together by snap interlocks which retain the contact blocks from separating.
It has been found, however, that although the stacked switches are secured together against longitudinal separation they frequently require additional interlock means to prevent their separation by lateral or twisting motion.
Associated with the foregoing is a problem of maintaining the movable contacts in the contact block within the normal or spring-biased position when the electric switch is subjected to abnormally high vibrations or shock. For example, switches used on board naval vessels require that electric circuits be undisturbed during shell fire. The shock of shell fire causes considerable impact and vibration on the switches. Under some circumstances where the switches are in the open position it is desirable to maintain certain ancillary circuits in the open or closed position without interference from shocks incurred by shell fire.